1. Technical Field
The disclosure relates to a through silicon via (TSV) repair circuit of a semiconductor device applied to chip stacking technologies.
2. Description of the Related Art
As the semiconductor process technologies have developed, areas of integrated circuits (ICs) have been reduced and the number of transistors in a single IC has been increased, thereby leading to an increase in IC usage area and severe delay time and power consumption of signals. In order to solve problems such as severe delay time and power consumption, a three-dimensional IC (3-D IC) stacking technology is considered to be an effective solution and has been vigorously researched in recent years. In the 3-D IC stacking technology, a plurality of chips or dies are stacked vertically in a three-dimensional space to achieve the benefit of reduced sizes. A through silicon via (TSV) structure passing through substrates is used to transmit signals between different chips, and thus the interconnection length of transistors and delay time in a 3-D IC are much shorter than those in a transitional two-dimensional IC while the 3-D IC performance is increased and the 3-D IC power consumption is reduced at the same time.
Since layers of integrated circuits have to be stacked precisely when chips are stacked, a small stacking offset could result in TSV connection failure among the chips. In addition, in order to utilize areas of the chips effectively, the TSV size is the smaller the better. Nevertheless, in the TSV manufacturing process, a sidewall insulation layer (for example, SiO2) is easily to be damaged or intruded by external impurity when being manufactured, resulting in a short circuit between the TSV and the substrate. Moreover, during the stack package process, an open defect may occur when TSVs in layers are being connected to each other. Therefore, a double TSV pair comprising of two TSVs is usually used to transmit signals in a 3-D IC. If one TSV of the double TSV pair has a defect, the other TSV of the double TSV pair can be used to transmit signals, thereby repairing the defective TSV. However, in this case, a leakage current will flow to the substrate via the defective TSV, thereby causing drift and instability of the global substrate voltage level and signal transmission failure.
In view of this, how to self-detect defects of TSVs and repair transmitting signals is an important issue in 3-D ICs.